US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
405 PM EDT Thu Aug 08 2019
 
Valid Sunday August 11 2019 - Thursday August 15 2019
 
Hazards:
- Heavy rain across portions of the Northern Plains, Sun, Aug 11.
- Heavy rain across portions of the Central Plains, the Middle Mississippi Valley, the Great Lakes, 
the Upper Mississippi Valley, and the Northern Plains, Mon, Aug 12.
- Flooding occurring or imminent across portions of the Northern Plains.
- Flooding likely across portions of the Central Plains, the Middle Mississippi Valley, and the 
Northern Plains.
- Excessive heat across portions of the Central Plains, the Lower Mississippi Valley, the Tennessee 
Valley, the Middle Mississippi Valley, the Southeast, the Southern Plains, and the Ohio Valley, 
Sun-Wed, Aug 11-Aug 14.
- Excessive heat across portions of the Southeast, the Mid-Atlantic, the Southern Appalachians, and 
the Tennessee Valley, Tue-Wed, Aug 13-Aug 14.
- High winds across portions of the Aleutians, Wed-Thu, Aug 14-Aug 15.
- High significant wave heights for coastal portions of the Aleutians, Wed-Thu, Aug 14-Aug 15.
 
Detailed Summary:

A strong upper level high will meander over eastern Texas and the lower Mississippi Valley next 
week which will sustain above average temperatures. Daily maxes will range from the upper 90s to 
low 100s with dew points in the upper 60s/lower 70s in western areas to the middle and upper 70s 
near the Mississippi River and along the Gulf Coast. This will result in maximum heat indices of 
105-110 degrees over much of eastern Texas with values around 115 degrees over southeastern Texas 
and northern Louisiana/southern Arkansas northeastward toward the Memphis area. This heat dome may 
expand eastward into the Southeast coastal plain next Tue/Wed ahead of an approaching front, which 
may temper the heat by next Thursday. 

To the north, heavy rain will be possible Sun/Mon ahead of a cold front moving out of Montana and 
through the High Plains. On Sunday, focus will be through the Dakotas later in the day and possibly 
overnight as low pressure heads eastward. On Monday and into the overnight hours the rain will push 
southeastward into Iowa with some north-south spread in the recent model guidance. Thereafter, the 
system will continue moving eastward and southward but confidence decreases in location/timing of a 
heavy rain threat. 

Monsoonal moisture flowing through eastern Arizona and the Four Corners region could cause locally 
heavy rainfall and localized flash flooding as afternoon and evening showers and thunderstorms 
continue on Sunday and perhaps Monday, enhanced by a surge out of Mexico. No area was drawn as 
heavy rain may be rather isolated. 

Over Alaska, a respectably deep surface cyclone is forecast to approach the western Aleutians next 
Wednesday and into the Bering Sea Thursday, spreading rain and high winds across parts of the 
island chain. Waves may near 20ft on the Pacific side per the ensemble probabilities generally west 
of Dutch Harbor. The system is forecast to lift northward next Thursday with the threat confined to 
the Aleutians. 

Fracasso